Breast cancer – about | Mate pukupuku ūtaetae

Breast cancer (mate pukupuku ūtaetae) is a harmful growth that starts in your breast tissue. It's the most common cancer among New Zealand women, affecting 1 in 9 women over their lifetime.

On this page, you can find the following information:

On average, 9 people in Aotearoa New Zealand, will hear the news today that they have breast cancer. 

Breastscreen Aotearoa is a national screening programme providing free mammograms to women aged 45 to 69 years, every 2 years. This service helps to catch breast cancer early and save lives. Read more about breast screening.

Men can develop breast cancer, though this is rarer, adding up to about 1% of all breast cancers.

Key points:

  • Breast cancer can occur at any age but is most common in women between 50 and 70 years old. You are more at risk if you have a family history of breast cancer.
  • Treatment is usually more successful if breast cancer is found at an early stage.
  • For this reason, women are advised to have a free mammogram every 2 years from 45 to 69 years old and regularly self-check their breasts. Read more and watch a video about how to check your breasts.
  • By the time you can feel a breast cancer, it's about the size of a cherry or walnut, while mammograms can pick up breast cancers that are as small as a grain of rice.
  • If you find a breast lump, see your healthcare provider to have it checked.

What are the causes of breast cancer?

Cancer is caused when some of the cells in our body start to grow out of control. These cells keep multiplying and form a lump called a tumour.

Some breast cancers grow very slowly, while others grow much faster. Breast cancer can spread to the lymph glands and to other parts of the body, such as the bones and liver.

The causes of breast cancer are not clear, but many risk factors are known. The main factors that influence your risk include being female and getting older. Most breast cancers are found in those who are 50 years old or older. Read more about risk factors for breast cancer.

What are the symptoms of breast cancer?

Breasts undergo changes throughout life. In particular, breasts may become sore, lumpy or swollen during the menstrual cycle. Not all breast lumps are caused by cancer, but some breast changes that may be early signs of cancer include:

  • a distinct lump or lumpiness
  • thickening of the tissue or skin
  • nipple changes, such as skin dimpling
  • a blood-stained discharge from one nipple
  • an inverted nipple (unless the nipple has always been turned in)
  • a rash on a nipple
  • a change in breast shape
  • a painful area
  • a rash or red mark that appears only on your breast.

If you have any of these changes. You don’t necessarily have breast cancer, but you should see your healthcare provider to get your breasts checked.

Most breast cancers begin in the milk ducts (ductal cancers), while a small number start in the milk sacs or lobules (lobular cancers). Within these 2 groups there are different subtypes of breast cancer.

How is breast cancer diagnosed?

Your healthcare provider will talk to you about your medical history and symptoms and will do a physical examination.

You may then be referred to a specialist for a mammogram and/or ultrasound scan. Further testing may be required including taking a sample of cells from the lump, biopsy or removal of the lump, and laboratory testing on any breast tissue samples.

Find out more about each of these diagnostic methods for breast cancer.

How is breast cancer treated?

Breast cancer is treated by 4 different methods: surgery, radiation treatment (radiotherapy), chemotherapy and hormone treatment. Find out more about each of these types of treatment for breast cancer. 

The treatment, or combination of treatments, used will depend on:

  • the type and size of the breast cancer
  • whether or not it has spread
  • the age, general health and personal choice of the person with breast cancer.

Understand your options

Before any treatment begins, make sure you have discussed the options with your healthcare provider. They may advise that one method of treatment is better than another, or that a combination of treatments is used. It's best to discuss these recommendations to help you understand the reasons for this advice. It is also your right to ask for a second opinion if you want one.

You may find it useful to have your partner, friend or whānau with you when you talk to healthcare providers. You may also find it helpful to make a list of questions before your visit. The Breast Cancer Foundation of NZ has an excellent webpage with questions to ask your surgeon and oncologist about your diagnosis and treatment.

Your treatment team

If you are diagnosed with breast cancer, you will be cared for by one or more of a team of health professionals, including:

  • your family healthcare provider
  • breast care and oncology nurses – who help you through all stages of your cancer treatment
  • a breast surgeon – who specialises in breast diseases, and sometimes a plastic (reconstructive) surgeon
  • a pathologist – a doctor who diagnoses disease by studying cells and tissues under a microscope
  • a radiation oncologist – a doctor who specialises in the use of radiation in the treatment of cancer
  • a radiation therapist – who prepares you and gives you your radiation treatment
  • a medical oncologist – a doctor who specialises in the use of drug treatments for cancer
  • a dietitians – who recommends the best foods to eat
  • social workers, physiotherapists and occupational therapists – who advise you on the support services available, and help you get back to normal activities.

In some areas, not all types of diagnosis and treatment are available. If there are services you would like to access, or you have questions about your symptoms, contact your breast care nurse so they can help you to get the best treatment.   

What happens after breast cancer treatment?

After your treatment is finished, you will have regular check-ups. Your healthcare provider will decide how often these are needed. They will gradually take place less often if you have no further problems. 

You should also regularly examine your breasts, or remaining breast and mastectomy area. Tell your doctor about any unusual breast symptoms or general health symptoms.

Many people worry that any pain or illness is a sign the cancer is coming back. This is usually not the case, but if you are worried, talk to your doctor about what you are experiencing.  

Cancer recurrence

Sometimes, breast cancer can come back. This is called a recurrence. Most recurrences appear within 5 years of the initial treatment. 

Treatment of recurrent breast cancer may be by surgery, radiation treatment, chemotherapy or hormone treatment or a combination of these. Treatment aims to control the disease. 

Successful treatment of recurrent breast cancer allows many people to continue leading normal lives. 

Common concerns following breast cancer treatment

Following breast cancer treatment, it's natural to have many questions and concerns that reach beyond whether the initial cancer has been cured.

Your recent experiences mean you may need access to good advice on how to best cope with the physical, emotional and psychological upheaval breast cancer has had on your life.  

Find out about common concerns after breast cancer treatment. 

Support and personal stories

Breast Cancer Support Inc. One-on-one calls, support, groups, step by step support pack and more.
Personal stories (English and Maori) National Screening Unit, NZ
What can you do for someone who is diagnosed? NZ Breast Cancer Foundation, 2013
Support for positive lives with secondary breast cancer Sweet Louise, NZ
More breast cancer support groups

Learn more

NZ Breast Cancer  NZ Breast Cancer Foundation
NZ Breast Cancer facts and statistics NZ Breast Cancer Foundation
Breast screening resources Time to Screen, NZ


  1. Breast Cancer Foundation NZ, 2017
  2. Fact sheets Breast Cancer Foundation, NZ, 2022 
  3. Questions to ask Breast Cancer Foundation, NZ, 2022
Credits: Cancer Society NZ & Health Navigator Editorial Team. Reviewed By: Dr Bryony Harrison, MBChB, BMedSci(Hons), DipPCEPE, Junior Doctor. Last reviewed: 03 Mar 2023